<!DOCTYPE html>
<html lang='en'>
<head>
    <meta charset='UTF-8'>
    <meta name='viewport' content='width=device-width, initial-scale=1.0'>
    <title>Document</title>
    <script type='text/javascript' src='js/vue.js'></script>
    <style>
        .cc{
            color:red;
        }

        .dd{
            color:blue
        }
    </style>
</head>
<body>
    <div id='app'>
        
        <div :class="[aa,bb,flag?cc:'']">1111133334444</div>
        <div :class="{cc:flag}" @click="change">66666</div>

        
    </div>
    <script type='text/javascript'>
        var vm = new Vue({
            el: '#app',
            data: {
                msg: 'Hello Vue',
                list:[1,2,3],
                aa:"active1",
                bb:"active2",
                flag:false,
                cc:'dd'
            },
            methods:{
                change(){
                    this.flag=!this.flag
                }
            }

        });
    </script>
</body>
</html>